HYPERSONIC REACTIVE FLOW COMPUTATIONS

Finite-volume and finite-element solutions to the Euler equations are presented for the computation of hypersonic reactive flows around blunt bodies. The basic numerical method is explicit for the time integration. Robust spatial approximations are constructed from either first-order or M.U.S.C.L.-type quasi second-order upwind schemes in which the flux-vector splitting accounts for a mixture of 5 perfect gases (N2, O2, NO, N and O) in the equation of state and for a local value of the parameter γ, here defined as the ratio of enthalpy to internal energy. Equilibrium flow solutions are found by combining the basic method with a classicial algebraic model, solved by Newton's method. Solutions to recently proposed non-quilibrium chemistry models are found by integrating forward in time additional transport equations. Treating the convection term explicitly, and the source term implicitly, the timestep is only moderately reduced. The effects on the equilibrium/non-equilibrium flow of the freestreatm Mach numver, Mχ, and the nose radius,Rb, are evaluated. In particular, it is verified that as Rb → ∞ (Mχ being fixed), the non-equilibrium flow solver does produce the equilibrium solution. © 1990.